Facial Mobility After Bimaxillary Surgery in Class III Patients

Abstract

Quantifying soft tissue changes after orthognathic surgery is increasingly important in surgical planning, but little is actually known about the changes in facial mobility after surgery. In the current study, we investigated facial mimics in patients before and after orthognathic surgery. Eleven patients with jaw discrepancy requiring maxillary and/or mandibular surgery were considered. Facial landmarks were applied, and facial surface data were acquired using a three-dimensional laser scanner before surgery and after 3, 6, and 12 months. The facial movements were frowning, eye closure, grimace, smiling, and lip purse. They were described in terms of surface and landmark displacements. Mean and SD were calculated for the right and left sides of the face and compared with normal values previously obtained in control subjects. We compared the results in 4 groups of patients: all the patients together (group A), bimaxillary surgery (group B), basal surgery without ancillary procedures (group C), and basal surgery plus rhinoplasty and/or genioplasty (group D). After surgery, modifications of symmetry were evident in many subjects, but after 1 year, facial movements were statistically similar to presurgical registrations. In smiling, the single case observations revealed a postsurgical improvement of amplitude in 8 subjects. In conclusion, orthognathic surgery did not significantly modify facial mobility in the long term. On the contrary, the amplitude of movement during smiling seems to increase in the majority of subjects. Our evaluation of three-dimensional laser scanning of facial movement showed that it can detect small posttreatment changes on soft tissues.

The Impact of Orthognathic Surgery on Facial Expressions

“…It also is valuable to evaluate the changes in the pattern and magnitude after orthognathic surgery, which can affect the stability of the achieved results. 6,9,16,17 Various 3D dynamic motion analysis systems have been used for the assessment of facial expressions. These systems track markers on the face or track pixels of the facial images.…”

“…A 3D laser scanner was used to assess the effect of orthognathic surgery on facial expressions 16 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 at 3, 6, and 12 months postoperatively. The displacement of every landmark at specific intervals was investigated.…”

“…9 Several studies have assessed the impact of orthognathic surgery on the bony structures and the covering soft tissue [10][11][12][13][14] ; however, the impact of orthognathic surgery on the dynamics of facial expressions is rarely investigated. 9, [15][16][17] The published studies on this topic have limitations. The direct placement of multiple markers on a patient's face before image captures can vary between imaging sessions, which introduces inaccuracies into the assessment.…”

Quantification of Facial Movements by Optical Instruments

“…Facial motion was investigated with marker displacements; this method had already been successfully used in several laboratories, without interfering with the movement. 5,6,16,19,22,30,31,35,36 The different marking method depends on the kind of motion analyzer. In both approaches analyzed in this study, the markers have to be positioned on the face and subsequently semiautomatically tracked from the computerized recordings, whereas in other studies the facial characteristics were automatically singled out without previous marking.…”

“…These methods were found to be minimally disturbing and reliable and to accurately detect total and local motion during the performance of standardized facial animations. 4,5,16,21,30,31,33 They offer a valuable support for the extraction of numeric values, which are very useful in the differential diagnosis. 4,5,21,23,29,31 The aims of the current study were to assess the accuracy of displacements of tracing landmarks in standardized facial movements for optoelectronic motion analyzer and surface laser scanning, and to compare the 2 methods in healthy people.…”